One teaspoon of granulated white sugar contains about 15 calories, all from carbohydrates. That number is small on its own, but it adds up fast when you consider how many teaspoons end up in a cup of coffee, a bowl of cereal, or a can of soda. Here’s how the calories break down across different types and amounts of sugar, and what those calories actually do once they’re in your body.
Calories by Amount
A level teaspoon of white granulated sugar weighs about 4 grams and delivers 15.4 calories. A tablespoon, which is three teaspoons, comes to roughly 12 grams and 46 calories. A full cup of sugar weighs around 200 grams and packs close to 775 calories.
The quick math is straightforward: every gram of sugar contains just under 4 calories. If you’re reading a nutrition label that lists 24 grams of sugar, you’re looking at about 96 calories from sugar alone. To convert grams on a label into something more visual, divide by four. That 24 grams is six teaspoons of sugar.
How Different Sugars Compare
Brown sugar, white sugar, and powdered sugar are all nearly identical in calories. White sugar has 385 calories per 100 grams, while brown sugar comes in at 380 per 100 grams. The tiny difference comes from the molasses in brown sugar, which adds trace minerals and a small amount of water but no meaningful nutritional advantage. Powdered (confectioners’) sugar is simply white sugar that has been ground into a fine powder, so gram for gram, the calorie count is the same.
High fructose corn syrup, the sweetener found in most sodas and many processed foods, also lands at about 15 calories per teaspoon. Despite the ongoing debate about whether it’s worse for you than cane sugar, the two are virtually identical in caloric density.
Honey, Maple Syrup, and Other Natural Sweeteners
People often reach for honey or maple syrup assuming they’re lighter alternatives. Calorie-wise, the differences are small and sometimes work in the opposite direction from what you’d expect. Sugar is actually the most calorically dense of the three because it’s pure sucrose with no water content. Maple syrup is the lowest, and honey falls in between. But the gap is narrow enough that swapping one for another won’t meaningfully change your calorie intake. A tablespoon of honey runs about 64 calories, compared to sugar’s 46, because honey is denser and you end up using more by volume.
If you’re watching calories or trying to manage blood sugar, switching between natural sweeteners offers little practical benefit. The body processes all of them in similar ways.
What Sugar Calories Do in Your Body
Sugar calories aren’t just “empty” in the sense that they lack vitamins and minerals. They also behave differently from other carbohydrate calories once they hit your bloodstream. Table sugar (sucrose) is a 50/50 split of glucose and fructose. Your body handles those two molecules through very different pathways.
Glucose enters the bloodstream and triggers insulin release, which shuttles it into cells for energy. Most tissues in your body can use glucose directly. Fructose takes a different route: it goes almost entirely to the liver, where it gets converted into fat through a process the liver ramps up the more fructose it receives. Research published in The Journal of Clinical Endocrinology & Metabolism found that adults who drank sugar-sweetened beverages for just two weeks showed increased liver fat production and reduced insulin sensitivity compared to those drinking artificially sweetened beverages. That reduction in insulin sensitivity is the first step toward the kind of metabolic problems that lead to type 2 diabetes over time.
This doesn’t mean a teaspoon of sugar in your morning coffee is dangerous. It means that the total amount of sugar you consume across a full day matters more than any single serving, and liquid sugar (sodas, sweetened teas, juice) tends to deliver the largest doses because it’s easy to consume quickly without feeling full.
How Much Is Too Much
The Dietary Guidelines for Americans recommend keeping added sugars below 10 percent of your total daily calories. For someone eating 2,000 calories a day, that’s 200 calories from added sugar, or about 50 grams, which works out to 12.5 teaspoons. Children under 2 should avoid added sugars entirely.
To put that in perspective, a single 12-ounce can of cola contains about 39 grams of sugar, roughly 10 teaspoons, which gets you to nearly 80 percent of a full day’s limit in one drink. A flavored yogurt can add another 12 to 15 grams. Most Americans consume well over the recommended limit without realizing it, largely because sugar is added to foods that don’t taste particularly sweet: bread, pasta sauce, salad dressing, and flavored oatmeal.
Reading Labels Accurately
Nutrition labels list sugar in grams, which isn’t intuitive for most people. The simplest conversion: divide the grams by four to get teaspoons. A granola bar listing 16 grams of sugar contains four teaspoons. Current U.S. labels also separate “total sugars” from “added sugars,” which helps you distinguish the naturally occurring sugar in fruit or dairy from the sugar a manufacturer stirred in during processing. The calorie count per gram is the same either way, but naturally occurring sugars come packaged with fiber, protein, or fat that slows absorption, while added sugars typically do not.